   :origins       A mapping of layer names to their origin positions. Default
                  position is center. Positions can be :center :top :bottom
                  :left :right :top-left :top-right :bottom-left :bottom-right
+  :default       if true this becomes the default canvas
+  :default-layer specify a default layer. If unspecified, is the top layer
 
   and either:
 

  (:require-macros [cljs.core.async.macros :refer [go]])
)

(def canvas-store (atom {}))

(defn add!
  ([key canvas]
   (swap! canvas-store assoc key canvas))
  ([canvas]
   (add! :default canvas)))

(defn set-default-once!
  [canvas]
  (when-not (:default @canvas-store)
    (add! canvas)))

(defn remove!
  ([key]
   (swap! canvas-store dissoc key)))

(defn get
  ([key]
   (key @canvas-store))
  ([]
   (:default @canvas-store)))

(defn make
  "make a new pixi canvas, or initialise pixi with an existing canvas.


  :expand        if true makes the canvas take the entire window
  :engine        can be :webgl :canvas or :auto (default :auto)
  :default       true or false to set the default canvas to this
                 created one. defaults to true.

  and either:

